Machines, such as off-highway trucks and mining trucks, may employ one or more hydraulic systems to control various operations. For example, a hydraulic braking system can be employed to control driving speed of the machine, and a hydraulic pump can be employed to charge a hydraulic braking accumulator or accumulators of the hydraulic braking system. Similarly, a hydraulic steering system can be employed to steer the machine, and a hydraulic pump can be employed to charge a hydraulic steering accumulator or accumulators of the hydraulic steering system. Since such hydraulic systems operate with fluid, such as Nitrogen for an accumulator and oil for a hydraulic pump, maintenance activities may be carried out on the hydraulic systems to identify whether pressures of the hydraulic system and components thereof, such as an accumulator and a hydraulic pump, are at respective predetermined pressures or within respective predetermined pressure ranges. For example, pressure gauges may be manually connected to the accumulator and the hydraulic pump to detect respective pressures. However, each instance of manual pressure gauge connection can cause loss of pressure. As such, periodic connections of pressure gauges to hydraulic systems, over time, can cause hydraulic pressure characteristics to deviate from acceptable limits.
Japanese Publication Number 2009-264455, hereinafter referred to as the '455 publication, describes detecting an abnormal accumulator gas pressure drop during driving of a hydraulic pump. According to the '455 publication, a gas pressure drop detecting device for an accumulator is provided on a dump truck and includes a pressure sensor to detect the supply or supply stop of pressure oil to the accumulator during the driving of the hydraulic pump. The '455 publication also describes that the gas pressure drop detecting device includes a computing means to compute a determining element of determining an abnormality of gas pressure in the accumulator in accordance with a signal from the pressure sensor, namely, a charge cycle number (X/s) per unit time. A determining means of the gas pressure drop detecting device determines whether the computed charge cycle number (X/s) is considered to represent an abnormal drop, namely, a charge cycle number (Y/s) per unit time, or greater, and an output means outputs an abnormality signal when the determining means determines that the computed charge cycle number (X/s) is greater than or equal to the abnormal drop charge cycle number (Y/s).